Standard orthotopic heart transplantation versus total orthotopic heart transplantation. A transesophageal echocardiography study of the incidence of left atrial thrombosis.

BACKGROUND

After standard orthotopic heart transplantation (Sd HT), the enlarged resultant atria may promote atrial thrombosis. The purpose of this study was to compare the incidence of spontaneous echo contrast and left atrial thrombosis after Sd HT and total orthotopic (Tot HT) heart transplantation.

METHODS AND RESULTS

Transesophageal echocardiography (TEE) was performed in 75 patients with Sd HT and in 20 patients with Tot HT. Despite the use of antiplatelet therapy, an acute arterial embolism occurred in 11 (15%) of the 75 patients with Sd HT but in none of the 20 Tot HT patients. All patients were in sinus rhythm. Left ventricular ejection fraction was similar in Sd HT and Tot HT patients. Left atrial diameter was smaller in Tot HT patients than in Sd HT patients (41 +/- 4 versus 58 +/- 6 mm, P < .001). In Sd HT patients, spontaneous echo contrast was present in 43 patients (57%) and was associated with left atrial thrombus in 20 patients (on the left atrial appendage in 12 patients, on the posterior wall in 6, and on the suture in 2). No thrombus was detected by transthoracic echocardiography; all thrombi were detected by TEE. On the other hand, no left atrial thrombus was observed in Tot HT patients, and only 1 patient had spontaneous echo contrast. Of the 11 Sd HT patients who experienced an arterial embolism, 5 had both spontaneous echo contrast and left atrial thrombus and 5 had only spontaneous echo contrast.

CONCLUSIONS

This study demonstrates a high rate of left atrial thrombus after Sd HT and emphasizes the role of TEE in the follow-up of these patients. The therapeutic implications are the need for a preventive anticoagulant therapy in the high-risk population receiving Sd HT diagnosed with TEE and the consideration of Tot HT as a better surgical approach as far as thrombotic complications are concerned.